Developer Mode

Developer mode, often called dev mode for short, is activated when the game boots with additional memory allocation, enabling advanced debugging tools that can be accessed via in-game menus. These debugging tools are available in the original Jak and Daxter trilogy, as well as Jak X: Combat Racing.
Technical
Activation of developer mode is toggled independently from the cheat mode variable. It relies entirely on whether extra memory is allocated for debugging tools or not.
The easiest way to play the game with debugging tools enabled is to boot the game using the 'Play in Debug Mode' boot option in the OpenGOAL launcher. Other methods include emulating the game with xTVaser's PCSX2 128MB build or booting the game in a PlayStation 2 TOOL (DTL-T10000H) development console.